This invention generally relates to examining reviewing devices such as laryngoscopes, and particularly to an improved system to optically couple a light source in the handle thereof to a light conductor in the blade which supplies light to the field of view.
Laryngoscopes generally comprise a blade and a cooperating handle which are connected together in an L-shaped configuration. The handle normally serves as an enclosure for one or more batteries which energize a light source in the top of the handle. The switch for energizing the light source is usually positioned at the top of the handle, immediately adjacent to the light source and is activated by the blade when it is connected to the handle. Light from the light source is directed to the proximal end of a light conductor disposed in or on the blade. Light passes through the light conductor to the distal end thereof to illuminate field of view such as the patient's mouth and larynx during the examination thereof by medical personnel.
When using the device, the surface on the blade adjacent to the handle is used to press against the tongue and mandible of a patient in a supine position in order to prevent the patient's tongue from obstructing the view during visual examination of the larynx. The opposite blade surface is positioned opposing the upper front teeth of the patient which are occasionally used as a fulcrum to expose the larynx. While the instrument is useful in examining the larynx, the primary function of the laryngoscope is to expose the larynx in order to facilitate the insertion of an endotracheal tube into the trachea of the lungs to administer anesthetic gases.
In the prior examining devices, the light generated by the light source was not properly directed to the light receiving end of the light conductor so, that consequently, much of the light was lost either by being absorbed by the interior of the handle or by light rays which were scattered by the light source or reflector and which did not land on the receiving face of the light conductor. This poor optical coupling of the light source to the light conductor was not only an inefficient use of light, but the scattered or stray light rays tend to be distracting during the examination procedures and they tend to build up much heat.
While there has been a need to provide improved optical coupling between the light source and the light conductor in laryngoscopes and other examining devices, little improvement has been made in this particular area. The present invention provides an improved means to optically couple the light source in the handle to the light conductor associated with the blade, thereby resolving many of the aforesaid problems of the prior devices.